Interlocking adapter, and method for operating electric apparatus in interlocking manner with working machine

ABSTRACT

An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every ½ cycle of the alternating-current voltage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation of application Ser. No. 16/232,827 filed Dec. 26,2018, which in turn claims the benefit of Japanese Patent ApplicationNo. 2017-253964 filed on Dec. 28, 2017 and No. 2018-049556 filed on Mar.16, 2018 with the Japan Patent Office, the entire disclosures of whichare incorporated herein by reference.

BACKGROUND

The present disclosure relates to a technique for operating an electricapparatus in an interlocking manner with a working machine.

Japanese Patent No. 4955332 discloses an interlocking adapter configuredto be attached to an electric outlet provided in a dust collector.

The interlocking adapter is configured to supply electric current to aresistor in the interlocking adapter from the electric outlet, inresponse to reception of an interlocking operation command transmittedfrom an electric power tool by a receiver of the interlocking adapter.

The interlocking adapter allows interlocking operation of the dustcollector with the electric power tool without supply of an alternatingcurrent (AC) voltage from the dust collector to the electric power tool,and also eliminates wiring between the dust collector and the electricpower tool.

The interlocking adapter further allows interlocking operation of anelectric apparatus, such as a dust collector, with not only an AC-drivenworking machine, such as an electric power tool operated by an ACvoltage, but also a battery-driven working machine.

SUMMARY

In this interlocking adapter, in order to cause the electric apparatusto operate in an interlocking manner with the working machine, it isnecessary to supply a load current, with which the electric apparatuscan detect operation of the working machine, from the electric outlet ofthe electric apparatus to an electric load such as a resistor, during aworking period of the working machine, as mentioned above.

Therefore, the interlocking adapter has to use an electric load whichcan be continuously supplied with a load current equivalent to theelectric current that flows during the operation of the working machine,resulting in upsizing of the interlocking adapter.

The electric load requires heat dissipation measures by means of a heatsink and the like, since heat is generated due to flow of the electriccurrent through the electric load. Such heat dissipation measures leadto upsizing of the interlocking adapter. The load current supplied tothe electric load is wasted.

In one aspect of the present disclosure, it is desirable to be able toreduce power consumption of an interlocking adapter, and downsize theinterlocking adapter.

An interlocking adapter in one aspect of the present disclosure includesa current path, an electric load, a switch, and a controller. Thecurrent path supplies a load current based on an alternating-currentvoltage received from an electric outlet provided in an electricapparatus. The electric load is provided in the current path. The switchis provided in the current path, and turned on and off. The current pathis completed in response to the switch being turned on. The current pathis interrupted in response to the switch being turned off. Thecontroller, in response to reception of an interlocking command signalfrom a working machine, turns on and off the switch in synchronizationwith a change of the alternating-current voltage so as to supply theload current from the electric outlet to the electric load. Thecontroller turns on and off the switch at a specified ratio of a timeevery ½ cycle of the alternating-current voltage.

In the interlocking adapter as such, upon causing the electric apparatusto operate in an interlocking manner with the working machine inresponse to reception of the interlocking command signal, the switch isnot merely turned on to supply the load current to the electric load,but is turned on and off at a specified ratio of a time every ½ cycle ofthe alternating-current voltage.

Therefore, as compared to the aforementioned interlocking adapterdisclosed in Japanese Patent No. 4955332, the interlocking adapter inthe one aspect of the present disclosure can reduce an amount of theload current (in other words, effective current) supplied to theelectric load in order to cause the electric apparatus operate in aninterlocking manner with the working machine, and reduce powerconsumption. Also, since the effective current supplied to the electricload can be reduced, the interlocking adapter in the one aspect of thepresent disclosure can reduce an amount of heat generation of theelectric load, and can be downsized.

The working machine and/or the electric apparatus may be a job-sitedevice for performing a physical task.

An on-period during which the switch is turned on in order to cause theelectric apparatus in an interlocking manner with the working machinemay be associated with a detection characteristic of the load currentused to determine whether the electric apparatus operates in aninterlocking manner with the working machine.

For example, in case that the electric apparatus is configured todetermine whether to start interlocking operation with the workingmachine based on the load current supplied after a zero-cross point ofthe alternating-current voltage, the controller may turn on the switchonly for a certain period after the zero-cross point every ½ cycle ofthe alternating-current voltage.

For example, in case that the electric apparatus is configured todetermine whether to start interlocking operation with the workingmachine based on the load current supplied before the zero-cross pointof the alternating-current voltage, the controller may turn on theswitch only for a certain period before the zero-cross point every ½cycle of the alternating-current voltage.

The controller may turn on and off the switch so that the switch isturned on once for a specified period within the ½ cycle of thealternating-current voltage.

The controller may turn on and off the switch so that the switch isturned on at least twice for a specified period within the ½ cycle ofthe alternating-current voltage.

In this case, usability of the interlocking adapter can be improved. Inother words, a user of the interlocking adapter can use the interlockingadapter to cause a different type of electric apparatus to operate in aninterlocking manner with the working machine.

The electric apparatus can be configured to continue operating of theelectric apparatus for a certain period even if supply of the loadcurrent is no longer detected once the electric apparatus detects thatthe load current is supplied from the electric outlet and startsinterlocking operation with the working machine.

For example, a dust collector, which is one example of the electricapparatus, can be configured to continue operating the dust collectorfor a certain period and suck dust around the dust collector, even afteroperation of the working machine stops.

In case that the electric apparatus is configured as above, thecontroller may supply the load current to the electric load inaccordance with an operation characteristic of the electric apparatus.

In other words, in this case, the controller, in response to receptionof the interlocking command signal, may alternately execute a conductionimplementation control and a conduction stop control so as totemporarily stop supply of the load current within a certain periodduring which the electric apparatus and the working machine continueinterlocking operation with each other after the electric apparatus canno longer detect the supply of the load current.

The interlocking adapter as such can further reduce the amount of theload current (effective current) supplied to the electric load, canreduce the amount of heat generation accompanying the supply of the loadcurrent, and can be further downsized.

The controller executing the conduction implementation control may turnon and off the switch for 1 cycle of the alternating-current voltage ora specified control period which is longer than the 1 cycle so as tosupply the load current from the electric outlet to the electric load.The controller executing the conduction stop control may turn off theswitch for 1 cycle of the alternating-current voltage or a specifiedstop period which is longer than the 1 cycle so as to stop the supply ofthe load current.

The controller, may select one of control patterns in accordance with aselection command received by the controller. The control patterns maybe different from each other in a ratio between an on-period of theswitch and an off-period of the switch.

In other words, the different type of electric apparatus can have adifferent detection characteristic of the load current used fordetermining whether to operate in an interlocking manner with theworking machine. The aforementioned controller can select one of thecontrol patterns in accordance with the type of the electric apparatus.

Use of the interlocking adapter as such allows the user to cause atleast two different types of electric apparatuses to operate in aninterlocking manner with the working machine. Also, in this case, sincethe controller can change the ratio of the time to turn on and off theswitch in accordance with the type of the electric apparatus, it ispossible to minimize the amount of the load current supplied to theelectric load in order to cause the electric apparatus to operate in aninterlocking manner with the working machine and downsize theinterlocking adapter.

The controller intermittently supplies the load current to the electricload by turning on and off the switch. The electric apparatus, based onthe load current, determines whether to operate in an interlockingmanner with the working machine.

The controller may accurately control the on-period and an off-period ofthe switch. In this case, the switch may include a semiconductor devicesuch as, for example, a field effect transistor (FET) and an insulatedgate bipolar transistor (IGBT) that can be turned on and off at adesired timing.

The interlocking adapter may further include a full-wave rectifierconfigured to rectify full wave of the alternating-current voltage andgenerate a rectified voltage.

In this case, the switch is turned on and off at a desired timing, sothat the load current can be supplied from the electric outlet to theelectric load. As a result, the electric apparatus can determine whetherto operate in an interlocking manner with the working machine based onthe load current.

The full-wave rectifier may include an input stage, and receive thealternating-current voltage at the input stage. The current path may becoupled to the input stage. The full-wave rectifier may include anoutput stage, and be configured to output the rectified voltage from theoutput stage. The current path may be coupled to the output stage.

A load characteristic (such as a resistance value) of the electric loadmay be set such that a value of the load current supplied during theon-period during which the controller turns on the switch is equal to orgreater than a current value for determining implementation ofinterlocking operation with the working machine by the electricapparatus.

The load current supplied to the electric load during the on-period ofthe switch can be determined from a value of the alternating-currentvoltage supplied from the electric outlet when the switch is on and theload characteristic of the electric load. In other words, when the valueof the alternating-current voltage is low, the load current can bereduced.

The interlocking adapter may include a voltage detector configured todetect the value of the alternating-current voltage. The controller mayadjust the ratio of the time, based on the value of thealternating-current voltage detected by the voltage detector. Thecontroller may adjust the ratio of the time so that the lower the valuedetected by the voltage detector is, the longer the switch is on.

In this case, without being influenced by fluctuation of thealternating-current voltage supplied from the electric outlet, it ispossible to control a magnitude of the load current supplied to theelectric load during the on-period of the switch to a desired magnitudeof the load current which allows determination on whether to implementinterlocking operation with the working machine by the electricapparatus. Thus, it is possible to cause the electric apparatus tooperate in an interlocking manner, in conjunction with operation of theworking machine more reliably.

The electric load may include a resistive load. The interlocking adaptermay include a fan configured to cool the resistive load.

The controller may drive the fan in synchronization with theinterlocking command signal.

The controller may stop the supply of the load current to the electricload in response to stop of reception of the interlocking commandsignal.

The controller may stop driving of the fan in response to elapse of aspecified cooling time after stopping the supply of the load current. Inthis case, even after the supply of the load current to the electricload is stopped, it is possible to continue cooling of the electric loadand inhibit an increase in temperature of the interlocking adapter.

The interlocking adapter may include a temperature detector configuredto detect a temperature of the electric load.

The controller may continue driving of the fan in response to thetemperature, which is detected by the temperature detector, being equalto or higher than a specified temperature after the supply of the loadcurrent is stopped. In this case, it is possible to inhibit an increasein temperature of the interlocking adapter due to heat generation of theelectric load after the supply of the load current to the electric loadis stopped.

The controller may determine whether the fan is normally (or properly)rotating during the supply of the load current to the electric load. Thecontroller may stop the supply of the load current to the electric loadin response to determination by the controller that the fan is notnormally rotating.

In this case, it is possible to inhibit excessive heat generation of theelectric load due to failure of the fan to cool the electric load duringthe supply of the load current to the electric load.

When the supply of the load current to the electric load is forciblystopped due to failure of the fan, it is not possible to cause theelectric apparatus to operate in an interlocking manner with the workingmachine.

The interlocking adapter may be configured to perform error display whenthe supply of the load current to the electric load is forcibly stopped.In this case, it is possible to notify the user that a reason why theelectric apparatus cannot operate in an interlocking manner with theworking machine is due to failure of the interlocking adapter.

The interlocking adapter may include a housing including a first outerwall surface. The interlocking adapter may include a power cord coupledto the electric outlet. The fan may be housed in the housing togetherwith the electric apparatus. The first outer wall surface may include afirst opening provided to suck an air into the housing or discharge theair from the housing. The first outer wall surface may include aninsertion hole provided to insert the power cord into the housing. Thepower cord may be drawn out from the insertion hole to outside of thehousing.

In this case, it is possible to inhibit or restrict the power cord fromclosing the first opening. Therefore, it is possible to secure a suctionpath of the air from the first opening or a discharge path of the air tothe first opening, and cool the electric load by rotation of the fan.

In case that the fan is arranged near the first opening, a forced airflow can be generated through the first opening which is not to beclosed. Therefore, the electric load can be more effectively cooled.

The housing may include a second outer wall surface. The second outerwall surface may include a second opening provided to suck an air intothe housing or discharge the air from the housing.

The housing may include a third outer wall surface. The third outer wallsurface may include a third opening provided to suck an air into thehousing or discharge the air from the housing.

In this case, a passage of the air can be formed by the second openingand the third opening, in addition to the first opening. Further, evenif any one of the first opening, the second opening and the thirdopening is closed, the passage of the air can be secured. Thus, coolingeffect of the electric load by rotation of the fan can be sufficientlyexerted.

The first opening, the second opening and the third opening may bearranged so as to face the electric load. The fan may be arrangedbetween one of the first opening, the second opening and the thirdopening, and the electric load.

In this case, it is possible to concentrate an air flow generated byrotation of the fan on the electric load and inhibit heat from theelectric load from flowing into other portion in the housing, therebyinhibiting an increase in temperature of the interlocking adapter.

The interlocking adapter may be configured to notify the user of thecontrol pattern selected by the controller.

This notification may be performed, for example, by lighting of a LED,image display or the like. The housing may include an operating devicethat receives the selection command from the user. An indicator thatmakes the aforementioned notification may be arranged so as to avoidbeing covered by a hand of the user operating the operating device. Evenwhen the error display is performed due to failure of the fan or thelike, the indicator may avoid being covered by the hand of the user.

When the indicator for displaying an operation state such as theselected control pattern, an error, etc. is provided in the interlockingadapter, the indicator and the operating device may be provided on thesame outer wall surface of the housing. The indicator may be arranged atan outer side of the housing than the operating device (in other words,a corner portion).

In the arrangement as above, when the user is operating the operatingdevice while holding the housing with the hand, it is possible for theindicator arranged at the outer side of the housing to avoid beingcovered by the hand of the user. Therefore, the user can check theindicator while operating the operating device.

Another aspect of the present disclosure is a method for operating anelectric apparatus in an interlocking manner with a working machine. Themethod includes: receiving an alternating-current voltage supplied froman electric outlet provided in an electric apparatus by an interlockingadapter; wirelessly receiving an interlocking command wirelesslytransmitted from a working machine by the interlocking adapter; andturning on and off a switch in the interlocking adapter insynchronization with a change of the alternating-current voltage inresponse to wireless reception of the interlocking command by theinterlocking adapter so as to supply a load current from the electricoutlet to an electric load in the interlocking adapter, the switch andthe electric load being provided in a path of the load current in theinterlocking adapter, the switch being turned on and off at a specifiedratio of a time every ½ cycle of the alternating-current voltage.

The method as above can exert the same effect as the aforementionedinterlocking adapter.

An interlocking adapter in further another aspect of the presentdisclosure comprises: a current path provided to supply a load currentbased on an alternating-current voltage received from an electric outletprovided in an electric apparatus; a capacitive load provided in thecurrent path; a switch provided in the current path and is configured tobe turned on and off, the current path being completed in response tothe switch being turned on, the current path being interrupted inresponse to the switch being turned off; and a controller configured toturn on and off the switch in synchronization with a change of thealternating-current voltage in response to reception of an interlockingcommand signal from a working machine to supply the load current fromthe electric outlet to the capacitive load, the controller beingconfigured to turn on and off the switch at a specified ratio of a timeevery ½ cycle of the alternating-current voltage.

In the interlocking adapter as above, consumption of electric power isreduced in the capacitive load. Since heat generation of the capacitiveload is inhibited, the interlocking adapter can be downsized.

The capacitive load may include a capacitor. The capacitor may have anequivalent series resistance (ESR), desirably a low ESR.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the present disclosure will be describedhereinafter with reference to the accompanying drawings, in which:

FIG. 1 is an explanatory view showing a configuration of an entireinterlocking system of a first embodiment;

FIG. 2 is a block diagram showing a configuration of an interlockingadapter of the first embodiment;

FIG. 3 is an explanatory view showing control patterns of a switchingpart set for each operation mode of the interlocking adapter;

FIG. 4A is a flowchart showing a part of a control process executed toturn on and off the switching part by a controller;

FIG. 4B is a flowchart showing the rest of the control process;

FIG. 5 is an explanatory view showing a variation of the control patternof the switching part;

FIG. 6A is a flowchart showing a first part of a control processexecuted in accordance with the control pattern of FIG. 5 ;

FIG. 6B is a flowchart showing a second part of the control process;

FIG. 6C is a flowchart showing a third part of the control process;

FIG. 6D is a flowchart showing the rest of the control process;

FIG. 7 is a block diagram showing a configuration of an interlockingadapter of a second embodiment;

FIG. 8A is a flowchart showing a part of a control process executed by acontroller of the second embodiment;

FIG. 8B is a flowchart showing the rest of the control process of thesecond embodiment;

FIG. 9A is a flowchart showing a part of a fan motor control processshown in FIGS. 8A and 8B;

FIG. 9B is a flowchart showing the rest of the fan motor controlprocess;

FIG. 10 is a flowchart showing a detail of a switching part failurediagnosis process shown in FIG. 8A;

FIGS. 11A-11E are explanatory views showing an appearance of aninterlocking adapter of the second embodiment, in which FIG. 11A is aplan view of the interlocking adapter, FIG. 11B is a side view of theinterlocking adapter seen from below in FIG. 11A, FIG. 11C is a bottomview of the interlocking adapter, FIG. 11D is a left side view of theinterlocking adapter, and FIG. 11E is a right side view of theinterlocking adapter;

FIG. 12 is a plan view of the interlocking adapter showing a state inwhich an upper housing of the interlocking adapter is removed;

FIG. 13 is a sectional view taken along a line XIII-XIII in FIG. 11 ;

FIGS. 14A and 14B are perspective views showing the appearance of theinterlocking adapter, in which FIG. 14A shows a state in which a hook ishoused, and FIG. 14B shows a state in which the hook is pulled out.

FIG. 15 is a perspective view of the interlocking adapter of the secondembodiment, showing a state in which the interlocking adapter isattached to a dust collector;

FIG. 16 is a perspective view of the interlocking adapter of the secondembodiment, showing a state in which a fixing band is attached to theinterlocking adapter;

FIG. 17 is a circuit diagram showing a configuration of an interlockingadapter of a reference example; and

FIG. 18 is a circuit diagram showing a variation of the interlockingadapter shown in FIG. 17 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

As shown in FIG. 1 , an interlocking system of the present embodimentincludes a circular saw 10 as one example of a working machine of thepresent disclosure. The interlocking system further includes a dustcollector 20, which operates in conjunction with the circular saw 10, asone example of an electric apparatus of the present disclosure.

The dust collector 20 includes a tank 22. The dust collector 20 includesa dust collector main body 30 on top of the tank 22. The dust collectormain body 30 includes an alternating current (AC) motor (not shown) anda suction fan (not shown) in the dust collector main body 30. The dustcollector 20 includes a power cord 24 for receiving electric power froman AC power source (not shown) such as a commercial power source. Thepower cord 24 is drawn out from the tank 22.

The AC motor is driven by the electric power supplied from the AC powersource coupled via the power cord 24 and rotates the suction fan. Whenthe suction fan is rotated by the AC motor, a hose 28 coupled to asuction port 26 of the tank 22 sucks dust and the like around a leadingend portion of the hose 28 together with the air. The sucked dust andair pass through the tank 22 into the dust collector main body 30. Theair that has entered the dust collector main body 30 is discharged fromthe dust collector main body 30.

A filter (not shown) is provided between the tank 22 and the dustcollector main body 30. The filter captures the dust and the like suckedvia the hose 28. The captured dust and the like are collected in thetank 22.

The circular saw 10 includes a circular saw main body 12 including amotor (not shown). The circular saw 10 further includes a disc-shapedsaw blade 14 attached to a rotation shaft protruding from the circularsaw main body 12. The circular saw 10 further includes a blade case 16attached to the circular saw main body 12 to cover the saw blade 14. Theblade case 16 is coupled to the leading end portion of the hose 28 drawnout from the suction port 26 of the dust collector 20.

The dust collector 20, that operates in an interlocking manner with thecircular saw 10 cutting a workpiece, can suck dust produced from theworkpiece.

The dust collector main body 30 includes an electric outlet 32. Theelectric outlet 32 is provided to supply AC power to a working machinesuch as the circular saw 10. The dust collector main body 30 furtherincludes a controller 34. The controller 34 detects electric currentflowing from the electric outlet 32 to the working machine and drivesthe AC motor.

The dust collector 20 as such can operate in an interlocking manner, forexample, with an AC-driven working machine having an AC plug pluggedinto the electric outlet 32.

The circular saw 10 of the present embodiment includes an attachmentportion 18. The attachment portion 18 is configured to attach a batterypack 40 to the circular saw main body 12. The circular saw 10 isconfigured to drive a motor of the circular saw 10 by direct-current(DC) power supplied from the battery pack 40 attached to the attachmentportion 18.

The circular saw 10 includes a transmitter 42. The transmitter 42transmits an interlocking command signal in a wireless manner when themotor of the circular saw 10 is driven by operation of a user (in otherwords, when the workpiece is being cut). The interlocking command signalinstructs an electric apparatus such as the dust collector 20 to operatein an interlocking manner with the circular saw 10. The transmitter 42in another embodiment may also transmit an additional signal, inaddition to the interlocking command signal, in a wireless manner.

The electric outlet 32 of the dust collector 20 is coupled to aninterlocking adapter 50. The interlocking adapter 50 is configured toflow a specified load current into the interlocking adapter 50, inresponse to reception of the interlocking command signal transmittedfrom the transmitter 42.

The interlocking adapter 50 includes an AC plug 52. The AC plug 52 isplugged into the electric outlet 32 to be electrically coupled to thedust collector 20. The interlocking adapter 50 includes an adapter mainbody 54.

The adapter main body 54 receives the interlocking command signaltransmitted from the transmitter 42. The adapter main body 54 draw theload current from the dust collector 20 via the AC plug 52, in responseto reception of the interlocking command signal. The AC plug 52 isprovided at a leading end of a power cord 53 drawn out from the adaptermain body 54.

As shown in FIG. 2 , the adapter main body 54 includes a full-waverectifier 60. The full-wave rectifier 60 rectifies full wave of an ACvoltage supplied from the electric outlet 32 via the AC plug 52 and thepower cord 53 so as to generate a rectified voltage. The full-waverectifier 60 in the present embodiment may be provided with a bridgecircuit (so-called diode bridge) configured to rectify the AC voltagewith four diodes.

The rectified voltage generated by the full-wave rectifier 60 is appliedto a series circuit formed with a resistive load 62, a switching part64, and a current detector 66.

The resistive load 62 functions as an electric load through which a loadcurrent flows. The load current is used for the dust collector 20 todetect operation of the working machine. More specifically, theresistive load 62 of the present embodiment includes a resistor throughwhich the load current flows.

The switching part 64 couples/interrupts the resistive load 62 and thecurrent detector 66. The switching part 64 in the present embodimentincludes an insulated gate bipolar transistor (IGBT). The switching part64 in another embodiment may include another type of switching elementsuch as a field effect transistor (FET), instead of or in addition tothe IGBT.

The current detector 66 detects a value of the load current that flowsthrough the current detector 66. The current detector 66 further outputsa detection signal indicating the value of the detected load current.The current detector 66 may include a resistor coupled in series to theresistive load 62 via the switching part 64, and output a voltage acrossthe resistor as the detection signal.

The detection signal outputted from the current detector 66 is inputtedto a controller 70 and an overcurrent protector 79.

The overcurrent protector 79 forcibly turns off the switching part 64when the value of the load current detected by the current detector 66exceeds a threshold value preset for determination of overcurrent, so asto inhibit or restrain flowing of overcurrent to the resistive load 62.

The resistive load 62 is provided with a temperature detector 78including a thermistor. A detection signal (signal indicatingtemperature of the resistive load 62) outputted from the temperaturedetector 78 is inputted to the controller 70.

An output stage of the full-wave rectifier 60 (output stage of therectified voltage) is coupled to a zero-cross detector 68, in additionto the aforementioned series circuit. The zero-cross detector 68 detectsa zero-cross point of the AC voltage supplied from the electric outlet32 of the dust collector 20 to the AC plug 52, and outputs a detectionsignal indicating detection of the zero-cross point. The detectionsignal outputted from the zero-cross detector 68 is inputted to thecontroller 70.

More specifically, the zero-cross detector 68 detects a timing at whichthe rectified voltage applied from the full-wave rectifier 60 to thezero-cross detector 68 becomes zero, as the zero-cross point.

The output stage of the full-wave rectifier 60 is coupled to a controlpower supply 74 via a diode 72. The diode 72 is provided to inhibit orrestrain reverse flow of electric current from the control power supply74 to the output stage of the full-wave rectifier 60. The control powersupply 74 generates a power supply voltage (DC constant voltage) foroperating an internal circuit of the adapter main body 54, such as thecontroller 70, based on the rectified voltage supplied from thefull-wave rectifier 60.

A power supply voltage detector 76 is coupled to an input path of therectified voltage to the control power supply 74. The power supplyvoltage detector 76 detects a voltage value of the rectified voltage (inother words, voltage value of the AC voltage), and outputs a detectionvoltage indicating the detected voltage value to the controller 70. Thepower supply voltage detector 76 may include at least two resistors, andoutput a rectified voltage divided by these two resistors to thecontroller 70 as the detection voltage.

The controller 70 includes a micro control unit (MCU) including at leasta CPU, a ROM, and a RAM. Instead of or in addition to the MCU, thecontroller 70 may include, for example, a combination of electroniccomponents such as a discrete device, an Application SpecifiedIntegrated Circuit (ASIC), an Application Specific Standard Product(ASSP), a programmable logic device such as, for example, FieldProgrammable Gate Array (FPGA), or a combination of the foregoing. Thecontroller 70 executes a control process for supplying the load currentto the resistive load 62 when the interlocking command signal istransmitted from the transmitter 42 of the circular saw 10.

The controller 70 utilizes the zero-cross point of the AC voltagedetected by the zero-cross detector 68 and the voltage value of the ACvoltage detected by the power supply voltage detector 76, in order toexecute the control process.

The controller 70 further executes a protection process. In theprotection process, the controller 70 determines an overheated state ofthe resistive load 62, based on the temperature of the resistive load 62detected by the temperature detector 78 and the value of the loadcurrent detected by the current detector 66, and forcibly turns off theswitching part 64.

The adapter main body 54 is provided with a receiver 80. The receiver 80receives the interlocking command signal wirelessly transmitted from thetransmitter 42 of the circular saw 10 in a wireless manner. The adaptermain body 54 further includes an operating device 82. The operatingdevice 82 is utilized by a user of the interlocking adapter 50 tomanually perform mode setting of the interlocking adapter 50.

The operating device 82 includes a mode setting switch (not shown). Themode setting switch is operated so as to sequentially switch the modesetting of the interlocking adapter 50 to any one of a first mode, asecond mode, and a third mode to be described later.

The controller 70 is coupled to a reception input device 86. Thereception input device 86 receives a reception signal from the receiver80. The controller 70 is coupled to an operation input device 88. Theoperation input device 88 receives an operation signal from theoperating device 82.

The receiver 80 is a device separate from the adapter main body 54, oris included in a separate device. The receiver 80 is detachably attachedto the adapter main body 54. Assuming that the adapter main body 54 isconfigured to supply electric power from the control power supply 74 tothe receiver 80 when the receiver 80 is not attached to the adapter mainbody 54, the user may touch a terminal provided in the adapter main body54 in order to supply the electric power to the receiver 80 and get anelectric shock, or the control power supply 74 may fail.

In order to avoid such a risk, the interlocking adapter 50 includes aninsulation power supply 90. The insulation power supply 90 receives theAC voltage through the input path of the AC voltage from the AC plug 52.The insulation power supply 90 converts (steps down) the received ACvoltage with an isolation transformer, and then generates a power supplyvoltage for driving the receiver 80.

The receiver 80 receives the power supply voltage from the insulationpower supply 90. Therefore, even if the user touches the terminal forsupplying electric power to the receiver 80, direct application of theAC voltage from the AC plug 52 to the user can be avoided, and safety ofthe user can be ensured. The operating device 82 is a portion directlytouched by the user for operation. Therefore, the operating device 82receives the power supply voltage from the insulation power supply 90.

Assuming that the receiver 80 is directly coupled to the reception inputdevice 86 via a signal line, or the operating device 82 is directlycoupled to the operation input device 88 via a signal line, it may notbe possible to ensure safety of the user.

Thus, in the present embodiment, the receiver 80 is coupled to thereception input device 86 via a first photo coupler (not shown)including a first light emitting device (not shown) and a first lightreceiving device (not shown). The operating device 82 is coupled to theoperation input device 88 via a second photo coupler (not shown)including a second light emitting device (not shown) and a second lightreceiving device (not shown). Thus, the receiver 80 is electricallyisolated from the reception input device 86, and the operating device 82is electrically isolated from the operation input device 88, resultingin that safety of the user can be ensured.

A varistor 56 that functions as a surge absorber is provided in theaforementioned input path of the AC voltage. The varistor 56 protectsthe internal circuit from incoming noise.

The controller 70 is coupled to an indicator 84. The indicator 84displays the mode setting (first mode, second mode or third mode) setvia the operating device 82. The indicator 84 may include a LED, anddisplay the mode setting by lighting the LED.

As the mode setting that can be set via the operating device 82, thefirst mode, the second mode, and the third mode shown in FIG. 3 areprovided in accordance with the type of the dust collector 20 that canimplement interlocking operation using the interlocking adapter 50 ofthe present embodiment (more specifically, detection characteristic ofthe load current for determination of interlocking operation in the dustcollector 20).

In the first mode, the controller 70 turns off the switching part 64 fora certain off-period W1 after detection of the zero-cross point for eachdetection cycle (that is, ½ cycle of the AC voltage) of the zero-crosspoint (time point t0 shown in FIG. 3 ) by the zero-cross detector 68.The controller 70 thereafter turns on the switching part 64 for acertain on-period W2 till the next zero-cross point.

The second mode is different from the first mode in ratio between aperiod during which the switching part 64 is turned on and a periodduring which the switching part 64 is turned off. The controller 70 inthe second mode, as in the first mode, turns off the switching part 64for a certain off-period W1 for each ½ cycle of the AC voltage, andthereafter turns on the switching part 64 for a certain on-period W2.

In the third mode, the controller 70, after detection of the zero-crosspoint for each ½ cycle of the AC voltage, waits for a short off-period(W1) and then turns on the switching part 64. The controller 70 thenturns off the switching part 64 after a certain on-period W2 elapses.

The reason why the controller 70 in the third mode waits for a shorttime after detection of the zero-cross point and turns on the switchingpart 64 is because electric current flowing through the motor of theAC-driven electric power tool which is originally coupled to theelectric outlet 32 is delayed by about 0.1 ms with respect to a voltagephase. In other words, the controller 70 in the third mode waits for ashort time after detection of the zero-cross point and then turns on theswitching part 64, in order not to supply electric current for the delaytime.

The memory (for example, ROM) of the controller 70 stores the off-periodW1 and the on-period W2 as setting data for each of the first mode, thesecond mode, and the third mode. The off-period W1 corresponds to theperiod during which the switching part 64 is turned off after thezero-cross point of the AC voltage is detected, as described above. Theon-period W2 corresponds to the period during which the switching part64 is turned on after the off-period W1 elapses, as described above.

The off-period W1 and the on-period W2 shown in FIG. 3 respectivelyrepresent the off-period immediately after detection of the zero-crosspoint and the subsequent on-period, when the AC voltage has a frequencyof 50 Hz and the ½ cycle is 10 ms.

In the second mode, the controller 70 not only switches the on-state andthe off-state of the switching part 64 every ½ cycle of the AC voltage,but also executes a conduction implementation control for supplying theload current in a certain conduction implementation period W3. In theconduction implementation control, the controller 70 switches theon-state and the off-state of the switching part 64 to supply the loadcurrent to the resistive load 62.

After the conduction implementation period W3 elapses, the controller 70executes a conduction stop control in a certain conduction stop periodW4 thereafter. In the conduction stop control, the controller 70 holdsthe switching part 64 in the off-state and stops supply of the loadcurrent. After execution of the conduction stop control, the controller70 alternately executes the conduction implementation control and theconduction stop control each time the conduction implementation periodW3 or the conduction stop period W4 elapses.

Therefore, in the setting data of the second mode, as shown in FIG. 3 ,in order to alternately execute the conduction implementation controland the conduction stop control, time indicating the conductionimplementation period W3 and time indicating the conduction stop periodW4 are set. In the setting data of the first mode and the setting dataof the third mode, the conduction implementation period W3 and theconduction stop period W4 are set to 0.

Each of the conduction implementation period W3 and the conduction stopperiod W4 is set longer than 1 cycle of the AC voltage. The conductionimplementation period W3 may be set to any time during which the dustcollector 20 can determine implementation of interlocking operation. Forexample, the conduction implementation period W3 may be set to 1 cycleof the AC voltage.

Also, the conduction stop period W4 may be set shorter than operationcontinuation time from when the dust collector 20 stops detection of thespecified load current until driving of the AC motor is stopped.

The longer the conduction stop period W4 is, the smaller an amount ofcurrent (effective current) supplied to the resistive load 62 forinterlocking operation is, resulting in reduction in power consumptionof the interlocking adapter 50. The conduction stop period W4corresponding to 1 cycle of the AC voltage can reduce power consumption,as compared to continuous execution of the conduction implementationcontrol. Therefore, the conduction stop period W4, similar to theconduction implementation period W3, may be set to 1 cycle of the ACvoltage.

The control process executed by the controller 70 to operate the dustcollector 20 in an interlocking manner with the circular saw 10 will bedescribed.

As shown in FIGS. 4A and 4B, when the control process is started, thecontroller 70 checks the current mode setting (that is, whether it isthe first mode, the second mode, or the third mode) in S110. Thecontroller 70 reads a current voltage value Vnow of the AC voltage fromthe power supply voltage detector 76 in S120.

In S130, the controller 70 reads the off-period W1 and the on-period W2from the setting data corresponding to the current mode setting,corrects each of the off-period W1 and the on-period W2 using thevoltage value Vnow, and sets the corrected off-period W1 and thecorrected on-period W2 as a timer value for measurement by a timer.

As shown in FIG. 3 , when the AC voltage supplied from the electricoutlet 32 of the dust collector 20 decreases, the amount of the loadcurrent supplied to the resistive load 62 during the on-period W2 of theswitching part 64 decreases. There is a possibility that the dustcollector 20 can no longer determine implementation of interlockingoperation.

Therefore, each of the off-period W1 and the on-period W2 is correctedso that the amount of electric current flowing through the resistiveload 62 during the on-period W2 of the switching part 64 is an amountrequired for the dust collector 20 to determine implementation ofinterlocking operation, and set as the timer value.

In S130, the controller 70 corrects the off-period W1 and the on-periodW2 based on a ratio between a reference voltage value Vref correspondingto the setting data and the voltage value Vnow. More specifically, thecontroller 70 corrects the off-period W1 and the on-period W2 so thatthe on-period W2 is longer when the voltage value Vnow is lower than thereference voltage value Vref. When the voltage value Vnow is higher thanthe reference voltage value Vref, the controller 70 corrects theoff-period W1 and the on-period W2 so that the on-period W2 is shorter.

Next in S140, the controller 70 reads the conduction implementationperiod W3 and the conduction stop period W4 from the setting datacorresponding to the mode setting, and sets each of the periods W3, W4as the timer value.

In this way, when the timer value of each of the periods W1 to S4 isset, the controller 70 proceeds to S150, and determines whether theinterlocking command signal transmitted from the transmitter 42 of thecircular saw 10 is received by the receiver 80. If the interlockingcommand signal is not received (S150: NO), then the controller 70proceeds to S110. If the interlocking command signal is received (S150:YES), then the controller 70 proceeds to S160.

In S160, the controller 70 determines whether the zero-cross point ofthe AC voltage is detected by the zero-cross detector 68, and waits forthe detection of the zero-cross point (S160: NO). When the zero-crosspoint is detected (S160: YES), the controller 70 proceeds to S170, anddetermines whether the off-period W1 set as the timer value has elapsed,and waits for the elapse of the off-period W1 (S170: NO).

When it is determined in S170 that the off-period W1 has elapsed (S170:YES), the controller 70 proceeds to S180, switches the switching part 64from the off-state to the on-state, starts supply of the load current tothe resistive load 62, and proceeds to S190.

In S190, the controller 70, after switching the switching part 64 to theon-state in S180, determines whether the on-period W2 set as the timervalue has elapsed. In S190, if it is determined that the on-period W2has not elapsed (S190: NO), then the controller 70 proceeds to S200, anddetermines whether the temperature of the resistive load 62 detected bythe temperature detector 78 is normal (or proper), more specifically,whether it is lower than a maximum temperature set in advance.

In S200, if it is determined that the temperature of the resistive load62 is lower than the maximum temperature and is normal (S200: YES), thenthe controller 70 proceeds to S210, and determines whether a value ofthe load current detected by the current detector 66 is lower than amaximum value and is normal (or proper). In S210, if it is determinedthat the value of the load current is lower than the maximum value andis normal (S210: YES), then the controller 70 proceeds to S190 again,and determines whether the on-period W2 has elapsed.

In S200, if it is determined that the temperature of the resistive load62 is abnormal (or improper) (S200: NO) or in S210 that the value of theload current is abnormal (or improper) (S210: NO), then the controller70 proceeds to S220, executes an error process, and terminates thecontrol process. In the error process, the controller 70 switches theswitching part 64 to the off-state, and displays the abnormal state onthe indicator 84.

If it is determined in S190 that the on-period W2 has elapsed (S190:YES), then the controller 70 proceeds to S230, switches the switchingpart 64 to the off-state, and stops supply of the load current. Insubsequent S240, the controller 70 determines whether the conductionimplementation period W3 set as the timer value in S140 has elapsed. Ifit is determined in S240 that the conduction implementation period W3has not elapsed (S240: NO), then the controller 70 proceeds to S110. Ifit is determined in S240 that the conduction implementation period W3has elapsed (S240: YES), then the controller 70 proceeds to S260.

In S260, the controller 70 checks the current mode setting as in S110,and proceeds to S270. In S270, the controller 70 determines whether themode setting is changed. If it is determined that the mode setting ischanged (S270: YES), then the controller 70 proceeds to S120.

In S270, if it is determined that the mode setting is not changed (S270:NO), then the controller 70 proceeds to S280, and determines whether theinterlocking command signal is received by the receiver 80 as in S150.

If it is determined in S280 that the interlocking command signal is notreceived (S280: NO), then the controller 70 proceeds to S110. If it isdetermined in S280 that the interlocking command signal is received(S280: YES), then the controller 70 proceeds to S290, where it isdetermined whether the conduction stop period W4 set as the timer valuein S140 has elapsed after it is determined in S240 that the conductionimplementation period W3 has elapsed.

When it is determined in S290 that the conduction stop period W4 haselapsed (S290: YES), the controller 70 proceeds to S110. When it isdetermined in S290 that the conduction stop period W4 has not elapsed(S290: NO), the controller 70 proceeds to S260.

As above, the controller 70 executes the control process by way ofprocedures shown in FIGS. 4A and 4B, and thereby the on-state and theoff-state of the switching part 64 is switched in synchronization withthe change of the AC voltage, in accordance with the mode setting set byoperation of the user of the operating device 82.

The control pattern of the switching part 64 in each of the first mode,the second mode, and the third mode is set in advance as shown in FIG. 3. The switching part 64 is turned on and off at a specified ratio of atime every ½ cycle of the AC voltage.

Therefore, according to the interlocking adapter 50 of the presentembodiment, as compared to the aforementioned interlocking adapterdisclosed in Japanese Patent No. 4955332, it is possible to reduce theamount of the load current (in other words, effective current value)supplied to the resistive load 62 in order to operate the dust collector20 in an interlocking manner with the circular saw 10, and reduce powerconsumption. Since the load current supplied to the resistive load 62can be reduced, it is possible to reduce an amount of heat generation ofthe resistive load 62, and downsize the interlocking adapter 50.

In the mode setting of the interlocking adapter 50, the first mode, thesecond mode, and the third mode are set in accordance with the detectioncharacteristic of the load current of the dust collector 20 operated inan interlocking manner with the circular saw 10 using the interlockingadapter 50. The user can select the mode setting by operating theoperating device 82.

Therefore, by selecting the mode setting of the interlocking adapter 50in accordance with the type of the dust collector 20, the user can set asupply period of the load current, that is supplied to the resistiveload 62 to operate the dust collector 20 in an interlocking manner, to aminimum, and reduce power consumption of the interlocking adapter 50.

In the second mode, the control pattern of the switching part 64 is setso that the conduction implementation control and the conduction stopcontrol are alternately executed in accordance with an operationcharacteristic of the dust collector 20 during the interlockingoperation. Therefore, in the second mode, as compared to the first modeand the third mode, electric current supplied to the resistive load 62for interlocking operation can be further reduced.

The interlocking adapter 50 of the present first embodiment, byoperation of the operating device 82 to switch the mode setting, canoperate several types of dust collectors 20 in an interlocking manner.Therefore, usability of the circular saw 10 and/or the dust collector 20can be improved

[Variations]

One embodiment of the present disclosure has been described in theabove, but the interlocking adapter 50 of the present disclosure is notlimited to the aforementioned first embodiment, and can be practiced invarious modes.

In the aforementioned first embodiment, three modes in accordance withthe type of the dust collector 20, that is, three modes corresponding tothe detection characteristic of the load current in the dust collector20 are set, and the user selects one of the modes.

The control pattern of the switching part 64 shown in FIG. 5 is oneexample of a single control pattern from which any of a plurality oftypes of dust collectors specified in advance can detect the loadcurrent and determine implementation of interlocking operation.

The interlocking adapter 50 may switch the switching part 64 to theon-state or the off-state according to the single control pattern shownin FIG. 5 when receiving the interlocking command signal from thecircular saw 10. As a result, the user no longer requires change of themode setting. Usability of the interlocking adapter 50 can be enhanced.

The control pattern shown in FIG. 5 is set so as to have a firston-period and a second on-period every ½ cycle of the AC voltage. Theswitching part 64 is turned on in each of the first on-period and thesecond on-period.

A length of the second on-period (second half conduction on-period) isset such that the magnitude of the load current is alternately switchedto be large or small for each specified period W5, W6 which is longerthan 1 cycle of the AC voltage.

In the period W5, for every ½ cycle of the AC voltage, the switchingpart 64 is turned on for the same on-period W2 as the on-period W2 ofthe third mode of the aforementioned first embodiment in a first half ofthe ½ cycle. In the second half of the ½ cycle, the switching part 64 isturned on for the same on-period W4 as the on-period W2 of the secondmode of the aforementioned first embodiment.

In the W6, for every ½ cycle of the AC voltage, the switching part 64 isturned on for the same on-period W2 as the on-period W2 of the thirdmode of the aforementioned first embodiment in the first half of the ½cycle. In the second half of the ½ cycle, the switching part 64 isturned on for the same on-period W8 as the on-period W2 of the firstmode of the aforementioned first embodiment.

Therefore, by turning on and off the switching part 64 in the controlpattern of the present variation, the load current supplied by switchingthe mode setting in the aforementioned first embodiment can be suppliedin one control pattern.

Setting data of the control pattern in the period W5 include theoff-period W1, the on-period W2, the off-period W3, and the on-periodW4. The off-period W1 is set to a period during which the switching part64 is turned off after detection of the zero-cross point. The off-periodW2 is set to a period during which the switching part 64 is turned onafter elapse of the off-period W1. The off-period W3 is set to a periodduring which the switching part 64 is turned off after elapse of theon-period W2. The on-period W4 is set to a period during which theswitching part 64 is turned on after elapse of the off-period W3 untilthe next zero-cross point.

Setting data of the control patter in the period W6 includes theoff-period W1, the on-period W2, the off-period W7, and the on-periodW8. The off-period W1 and the on-period W2 are the same as theoff-period W1 and the on-period W2 in the period W5, respectively. Theoff-period W7 is set to a period during which the switching part 64 isturned off after elapse of the on-period W2. The off-period W7 is set tobe longer than the off-period W3 in the period W5. The on-period W8 isset to a period during which the switching part 64 is turned on afterelapse of the off-period W7 until the next zero-cross point. Theon-period W8 is set to be shorter than the on-period W4 in the periodW5.

As a result, in the period W6, as compared to the period W5, themagnitude of the load current supplied within ½ cycle of the AC voltageis reduced.

A control process will be described which is executed by the controller70 in order to turn on and off the switching part 64 in the controlpattern shown in FIG. 5 and supply the load current to the resistiveload 62.

As shown in FIGS. 6A-6D, in this control process, the controller 70first determines in S310 whether the interlocking command signaltransmitted from the transmitter 42 of the circular saw 10 is receivedby the receiver 80, and waits for reception of the interlocking commandsignal (S310: NO).

If the interlocking command signal is received (S310: YES), then thecontroller 70 proceeds to S320, and reads the voltage value Vnow of thecurrent AC voltage from the power supply voltage detector 76.

In subsequent S330, the controller 70, using the voltage value Vnow readin S320, corrects the periods W1 to W4, W7, W8 defined by the controlpattern.

This correction is a process for inhibiting or restricting fluctuationof the magnitude of the load current supplied to the resistive load 62caused by fluctuation of the AC voltage. By this process, each of theperiods W1 to W4, W7, W8 is corrected based on a ratio between thereference voltage value Vref corresponding to the setting data of thecontrol pattern and the voltage value Vnow, as in the aforementionedS130.

In S330, the controller 70 sets the corrected periods W1 to W4, W7, W8to the respective timers as the timer value.

In subsequent S340, the controller 70 reads the periods W5 and W6 fromthe setting data of the control pattern, and sets the read periods W5and W6 to the respective timers as the timer value.

After setting the timer values of the periods W1 to W8, the controller70 proceeds to S350, determines whether the zero-cross point of the ACvoltage has been detected by the zero-cross detector 68, and waits fordetection of the zero-cross point (S350: NO).

When the zero-cross point is detected (S350: YES), the controller 70proceeds to S360, determines whether the off-period W1 has elapsed basedon the timer value set to the timer after detection of the zero-crosspoint, and waits for elapse of the off-period W1 (S360: NO).

In S360, if it is determined that the off-period W1 has elapsed (S360:YES), the controller 70 proceeds to S370, switches the switching part 64from the off-state to the on-state, starts supply of the load current tothe resistive load 62, and proceeds to S380.

In S380, the controller 70 determines whether the on-period W2 haselapsed based on the timer value set to the timer after switching theswitching part 64 to the on-state in S370. If it is determined in S380that the on-period W2 has not elapsed (S380: NO), then the controller 70proceeds to S390, and determines whether the temperature of theresistive load 62 detected by the temperature detector 78 is normal.

In S390, when it is determined that the temperature of the resistiveload 62 is lower than the maximum temperature and is normal (S390: YES),the controller 70 proceeds to S400, and determines whether the value ofthe load current detected by the current detector 66 is normal. In S400,if it is determined that the value of the load current is lower than themaximum value and is normal (S400: YES), then the controller 70 againproceeds to S380, and determines whether the on-period W2 has elapsed.

If it is determined in S390 that the temperature of the resistive load62 is abnormal (S390: NO) or in S400 that the value of the load currentis abnormal (S400: NO), then the controller 70 proceeds to S470,executes the error process, and terminates the control process. In theerror process, the controller 70 switches the switching part 64 to theoff-state, and displays the abnormal state on the indicator 84.

If it is determined in S380 that the on-period W2 has elapsed (S380:YES), then the controller 70 proceeds to S410, switches the switchingpart 64 to the off-state, and stops supply of the load current. Insubsequent S420, the controller 70 determines whether the off-period W3has elapsed based on the timer value set to the corresponding timerafter turning off the switching part 64 in S410, and waits for elapse ofthe off-period W3 (S420: NO).

If it is determined in S420 that the off-period W3 has elapsed (S420:YES), then the controller 70 proceeds to S430, and switches theswitching part 64 to the on-state. In subsequent S480, the controller 70determines whether the on-period W4 has elapsed after switching theswitching part 64 to the on-state based on the timer value set to thecorresponding timer.

If it is determined in S480 that the on-period W4 has not elapsed, thenthe controller 70 proceeds to S450, and determines whether thetemperature of the resistive load 62 detected by the temperaturedetector 78 is normal.

If it is determined in S450 that the temperature of the resistive load62 is lower than the maximum temperature and is normal (S450: YES), thenthe controller 70 proceeds to S460, and determines whether the value ofthe load current detected by the current detector 66 is normal.

When it is determined in S460 that the value the load current is lowerthan the maximum value and is normal (S460: YES), the controller 70again proceeds to S480, and determines whether the on-period W4 haselapsed.

If it is determined in S450 that the temperature of the resistive load62 is abnormal (S450: NO) or in S460 that the value of the load currentis abnormal (S460: NO), then the controller 70 proceeds to S470,executes the error process, and terminates the control process.

When it is determined in S480 that the on-period W4 has elapsed, thecontroller 70 proceeds to S490, and switches the switching part 64 tothe off-state. In subsequent S500, the controller 70 determines whetherthe interlocking command signal is received by the receiver 80.

If it is determined in S500 that the interlocking command signal is notreceived (S500: NO), then the controller 70 proceeds to S310. If it isdetermined in S500 that the interlocking command signal is received(S500: YES), then the controller 70 proceeds to S510, and determineswhether the period W5 has elapsed based on the timer value set to thecorresponding timer. When it is determined in S510 that the period W5has not elapsed (S510: NO), the controller 70 proceeds to S550 to beexplained later. When it is determined in S510 that the period W5 haselapsed (S510: YES), the controller 70 proceeds to S520, and set 0seconds to the corresponding timer as the timer value of the period W5.

In subsequent S530, the controller 70 determines whether the period W6set as the timer value has elapsed after it is determined that theperiod W5 has elapsed. When it is determined in S530 that the period W6has not elapsed (S530: NO), the controller 70 in S580 reads the voltagevalue Vnow of the current AC voltage from the power supply voltagedetector 76, and in subsequent S590, using the read voltage value Vnow,corrects the periods W7, W8 defined in the control pattern.

In S590, the controller 70 set the corrected periods W7, W8 as the timervalues of the periods W3, W4, and proceeds to S570.

The reason why the controller 70 in S590 sets the corrected periods W7,W8 as the timer values of the periods W3, W4 is to change the controlpattern of the switching part 64 to a control pattern for supplying asmall current, and drive the switching part 64 in the changed controlpattern in the aforementioned process of S350 to S490.

When it is determined in S530 that the period W6 has elapsed (S530:YES), the controller 70 proceeds to S540, sets the timer values of theperiods W5, W6, and proceeds to S550.

The controller 70 reads the voltage value Vnow from power supply voltagedetector 76 in S550, and, using the read voltage value Vnow, correctsthe periods W3, W4 defined in the control pattern in subsequent S560.

In S560, the controller 70 further sets the corrected periods W3, W4 asthe timer values of the periods W3, W4, and proceeds to S570. In S570,the controller 70 corrects the periods W1, W2 based on the voltage valueVnow read in S580 or S550, and sets the timer values of the correctedperiods W1, W2 to the corresponding timers. When the process of S570 isexecuted, the controller 70 proceeds to S350, and executes the processesafter S350.

As above, when the controller 70 executes the control process shown inFIGS. 6A to 6D, it is possible to control the switching part 64 in thecontrol pattern shown in FIG. 5 and supply to the resistive load 62 theload current that can cause different types of dust collectors tooperate in an interlocking manner with the circular saw 10.

Second Embodiment

A second embodiment of the present disclosure will be described below.

The interlocking adapter 50 of the second embodiment has a configurationsubstantially similar to the interlocking adapter 50 of the firstembodiment. The second embodiment is different from the first embodimentin that a fan for cooling the resistive load 62 is provided in theadapter main body 54.

In the second embodiment, a difference from the first embodiment, suchas a driving method of the fan will be described, and the sameconfiguration as that of the first embodiment will not be repeated.

As shown in FIG. 7 , the adapter main body 54 includes a fan motor 92. Acooling fan 93 is integrally assembled to the fan motor 92 of the secondembodiment. The adapter main body 54 further includes a drive circuit94. The drive circuit 94 is configured to receive electric power fromthe control power supply 74 to drive the fan motor 92.

More specifically, the drive circuit 94 includes a FET 96 provided in acurrent path to the fan motor 92. The drive circuit 94 further includesa transistor 98. The transistor 98 is coupled to resistors so as to beturned on by a drive signal from the controller 70, set a voltage of agate of the FET 96 to low level, and turn on the FET 96.

The fan motor 92 is configured to output a pulse signal in accordancewith rotation of the fan motor 92. The pulse signal (rotation pulse) isinputted to the controller 70.

In addition to the switching part 64 and the current detector 66, aprotection switch 65 is provided in a current path passing through theresistive load 62 from the full-wave rectifier 60. In the secondembodiment, the switching part 64 functions as a switch to complete andinterrupt the current path passing through the resistive load 62 inorder to supply and interrupt the load current (hereinafter, theswitching part 64 is referred to as “conduction switch 64”). Theprotection switch 65 is provided so as to be able to interrupt thecurrent path passing through the resistive load 62 when the conductionswitch 64 fails.

The adapter main body 54 includes a mode indicator 84A instead of theindicator 84. The mode indicator 84A is configured to display theoperation mode by three LEDs. The adapter main body 54 further includesan error indicator 84B. The error indicator 84B is configured to displayerrors by lighting one LED.

The controller 70 in the second embodiment executes the control processby way of procedures substantially similar to those of the firstembodiment. However, since the adapter main body 54 in the secondembodiment includes the fan motor 92, the controller 70 in the secondembodiment, as shown in FIG. 8A, executes a fan motor control process ofS600 after setting the timer value in S140.

After executing the fan motor control process of S600, the controller 70proceeds to S800 to execute a failure diagnosis process of the switchingpart including the conduction switch 64 and the protection switch 65,and proceeds to S150.

When it is determined in S160 that the zero-cross point of the ACvoltage is detected by the zero-cross detector 68 (S160: YES), thecontroller 70 proceeds to S165 shown in FIG. 8B, and determines whetherfailure of the fan motor 92 is detected in the fan motor control processor whether failure of the switching part is detected in the switchingpart failure diagnosis process.

When it is determined in S165 that the fan motor 92 and the switchingpart are normal (or in proper condition) (S165: YES), the controller 70proceeds to S170. When it is determined in S165 that the fan motor 92 orthe switching part has failed, the controller 70 proceeds to S220 andlights the LED of the error indicator 84B.

In S220, the controller 70 lights the LED of the error indicator 84B andperforms error display also when it is determined in S200 or S210 thatthe detected temperature or the detected value of electric current areabnormal.

Since the conduction switch 64 and the protection switch 65 are providedin the current path passing through the resistive load 62, thecontroller 70, when controlling supply of the load current in S180 andS230, holds the protection switch 65 to be on-state and turns on and offthe conduction switch 64.

When it is determined in S150 that the interlocking command signal isnot received by the receiver 80 (S150: NO), the controller 70 in S250turns off the conduction switch 64 and the protection switch 65 andproceeds to S110.

The fan motor control process executed in S600 will be described.

As shown in FIGS. 9A and 9B, in the fan motor control process, thecontroller 70 determines first in S610 whether the fan motor 92 is beingdriven. If the fan motor 92 is not being driven (S610: NO), thecontroller 70 proceeds to S620 and determines whether the interlockingcommand signal is received by the receiver 80.

When it is determined in S620 that the interlocking command signal isreceived (S620: YES), the controller 70 in subsequent S630 drives thefan motor 92 and temporarily terminates the fan motor control process.When it is determined in S620 that the interlocking command signal isnot received (S620: NO), the controller 70 immediately terminates thefan motor control process.

When it is determined in S610 that the fan motor 92 is being driven(S610: YES), the controller 70 proceeds to S640, and determines whetherthe fan motor 92 is rotating normally based on the rotation pulseinputted from the fan motor 92.

When it is determined in S640 that the fan motor 92 is rotating normally(S640: YES), the controller 70 proceeds to S650, clears a stop timecounter that measures stop time of the fan motor 92, and proceeds toS660. In S660, the controller 70 determines whether a temperature of theresistive load 62 detected by the temperature detector 78 is a hightemperature equal to or higher than a specified temperature.

When it is determined in S660 that the resistive load 62 has the hightemperature (S660: YES), the controller 70 proceeds to S670, and clearsa non-reception time counter for measuring a non-reception time duringwhich the interlocking command signal is not received. When completingclearing of the non-reception time counter, the controller 70temporarily terminates the fan motor control process. When it isdetermined in S660 that the temperature of the resistive load 62 is nothigh (S660: NO), the controller 70 proceeds to S680, and determineswhether the interlocking command signal is received by the receiver 80.

When it is determined in S680 that the interlocking command signal isreceived (S680: YES), the controller 70 proceeds to S670, clears thenon-reception time counter, and temporarily terminates the fan motorcontrol process. When it is determined in S680 that the interlockingcommand signal is not received (S680: NO), the controller 70 proceeds toS690, updates (increments) the non-reception time counter, and proceedsto S700.

In S700, the controller 70 determines whether the non-reception time isequal to a specified time (T1) or more, based on a value of thenon-reception time counter updated in S690. If the non-reception time inS700 is equal to the specified time (T1) or more (S700: YES), then thecontroller 70 proceeds to S710, stops driving of the fan motor 92, andtemporarily stops the fan motor control process. If the non-receptiontime in S700 is smaller than the specified time (T1) (S700: NO), thenthe controller 70 temporarily terminates the fan motor control processimmediately.

The non-reception time counter is cleared not only when the interlockingcommand signal is received as mentioned above but also when theresistive load 62 has the high temperature. Therefore, the non-receptiontime counter is not updated (incremented) until the resistive load 62has a temperature lower than the specified temperature.

Thus, the fan motor 92 continues to rotate when the temperature of theresistive load 62 is high. When the temperature of the resistive load 62is lowered and time during which the interlocking command signal is notreceived elapses for the specified time (T1) or more, the fan motor 92is stopped.

When it is determined in S640 that the fan motor 92 is not rotatingnormally (in other words, the fan motor 92 is stopped, or is rotating atan extremely low speed) (S640: NO), the controller 70 proceeds to S720,and updates (increments) the stop time counter.

In subsequent S730, the controller 70 determines whether a stop state ofthe fan motor 92 (more particularly, state in which the fan motor 92 isstopped or is rotating at an extremely low speed) continues based on thevalue of the stop time counter. If the stop state does not continue(S730: NO), then the controller 70 proceeds to S660.

On the other hand, when it is determined that the stop state continues(S730: YES), the controller 70 proceeds to S740, detects failure of thefan motor 92, stores the detected failure, and proceeds to S710.

In other words, the controller 70, when the stop state continues for agiven length of time or more, determines that the fan motor 92 hasfailed and stops driving of the fan motor 92.

In the fan motor control process as such, the controller 70, when theinterlocking command signal is received by the receiver 80, startsdriving of the fan motor 92. Thereafter, when the interlocking commandsignal is no longer received and the stop state continues for thespecified time (T1) or more, the controller 70 stops driving of the fanmotor 92. When the temperature of the resistive load 62 is high, thecontroller 70 continues driving of the fan motor 92. When thetemperature of the resistive load 62 is lowered, and the specified time(T1) or more elapses, the controller 70 stops driving of the fan motor92.

Thus, according to the second embodiment, when electric current issupplied to the resistive load 62 for interlocking operation, it ispossible to inhibit increase in temperature of the adapter main body 54due to heat generation of the resistive load 62. Further, it is possibleto inhibit increase in temperature of the adapter main body 54 due toheat of the resistive load 62, after driving of the fan motor 92 isstopped.

The switching part failure diagnosis process executed in S800 will bedescribed.

As shown in FIG. 10 , in the switching part failure diagnosis process,the controller 70 determines in S810 whether the interlocking commandsignal is received by the receiver 80, and a change of state hasoccurred from a non-reception state of the interlocking command signalto a received state of the interlocking command signal.

When it is determined in S810 that a change of state has occurred (S810:YES), the controller 70 proceeds to S820. When it is determined in S810that a change of state has not occurred (S810: NO), the controller 70terminates the switching part failure diagnosis process.

In S820, the controller 70 sets the conduction switch 64 to theon-state, and the protection switch 65 to the off-state, and proceeds toS830. In S830, the controller 70 determines whether detection ofelectric current by the current detector 66 is normal (or proper), anddetermines whether the protection switch 65 set to the off-state isinterrupting the current path of the load current normally.

When it is determined in S830 that the detection of electric current bythe current detector 66 is normal (S830: YES), the controller 70proceeds to S840, sets the conduction switch 64 to the off-state and theprotection switch 65 to the on-state, and proceeds to S850. In S850, thecontroller 70 determines whether the detection of electric current bythe current detector 66 is normal, and whether the conduction switch 64set to the off-state is interrupting the current path of the loadcurrent normally.

When it is determined in S850 that the detection of electric current bythe current detector 66 is normal (S850: YES), the controller 70determines that both the conduction switch 64 and the protection switch65 are normal (or in proper condition), and proceeds to S860. In S860,the controller 70 sets the conduction switch 64 and the protectionswitch 65 to the off-state, and terminates the switching part failurediagnosis process.

When it is determined in S830 or S850 that detection of the electriccurrent by the current detector 66 is abnormal (or improper) (S830 orS850: NO), there is a possibility that the protection switch 65 or theconduction switch 64 has failed. The controller 70 proceeds to S870,stores the failure of the switching part, and proceeds to S860.

In the switching part failure diagnosis process, the controller 70 setsone of the conduction switch 64 and the protection switch 65 to theoff-state and determines whether the load current is detected by thecurrent detector 66, thereby detecting the failure of the switching partset to the off-state.

When detecting the failure of the conduction switch 64 or the protectionswitch 65 in the switching part failure diagnosis process, or detectingthe failure of the fan motor 92 in the fan motor control process, thecontroller 70 determines occurrence of failure in the determinationprocess of S165, and prohibits supply of electric current to theresistive load 62. In this case, the controller 70 performs errordisplay to the error indicator 84B in the error process of S220.

Thus, the user, when it is not possible to operate the dust collector 20in an interlocking manner, can confirm that the cause is the failure ofthe interlocking adapter 50 from the error display of the errorindicator 84B.

When performing the error display in the error process in S220, thecontroller 70 may not only merely stop supply of electric current to theresistive load 62, but also may continue the error display duringreception of the interlocking command signal by the receiver 80.Alternatively, the controller 70 may continue error display until elapseof the given length of time from when the interlocking command signal isno longer received by the receiver 80.

If the error display continues as mentioned above, then failure of theinterlocking adapter 50 can be notified to the user even when the useris away from the interlocking adapter 50 and cannot immediately checkthe error display. The controller 70, when performing the error displayin S220, may notify the error by sound such as sounding a buzzer at thesame time.

In the error process of S220, the controller 70, depending on detail ofthe detected failure, may notify the user of the detail of the failuresuch as by changing a display manner of the error or sounding pattern ofthe buzzer. Specifically, a notification manner of error may be changeddepending on the detail of the failure. For example, failure of the fanmay be notified by turning on a red light or sounding of the buzzer, andfailure of the switch may be notified by flashing a red light orintermittent sounding of the buzzer. As a result, the user can detectthe detail of the failure.

The controller 70 may execute the error process of S220 also when thepower supply voltage detected by the power supply voltage detector 76 isout of a guaranteed operating range, or when the frequency of the powersupply voltage is out of the guaranteed operating range.

The controller 70 may not only perform the error display in the errorprocess of S220 but also report error to the tool (for example, circularsaw 10) by wireless communication. In this case, it is possible tonotify the user of the error via the tool. The user can more reliablydetect the failure of the interlocking adapter 50 by the notification.

A structure of the interlocking adapter 50 (specifically, adapter mainbody 54) of the second embodiment will be described.

As shown in FIGS. 11A to 11E, the adapter main body 54 includes arectangular housing 100. The housing 100 houses the aforementionedcomponents including the resistive load 62 and the fan motor 92.

The housing 100 includes an upper case 101 and a lower case 102, and isassembled as a single housing having an internal space. Specifically, anopening portion of the upper case 101 is overlapped with an openingportion of the lower case 102, and the upper case 101 is coupled to thelower case 102 by screws.

As shown in FIG. 11A, an outer wall surface of the upper case 101 facingthe lower case 102 is provided with a protective cover 80A which coversthe receiver 80 housed in the housing 100.

The receiver 80, as shown in FIG. 12 , is coupled to a connector 86A ofthe reception input device 86 inside the housing 100. Therefore, theuser can open the protective cover 80A, and couple the receiver 80 tothe connector 86A or detach the receiver 80 from the connector 86A.

As shown in FIG. 11B, the housing 100 is provided with an operationpanel 85. The operation panel 85 is positioned on the lower side in FIG.11A, and provided on a side wall along a longitudinal direction of thehousing 100. The operation panel 85 is provided with the three LEDsincluded in the mode indicator 84A. The operation panel 85 is providedwith the one LED included in the error indicator 84B. The operationpanel 85 is further provided with the switch included in the operatingdevice 82.

The receiver 80 and the operation panel 85 are arranged at a positionbiased in one direction (left direction in FIG. 11B) from a longitudinalcenter portion of the housing 100. As shown in FIGS. 11A to 11C, thehousing 100 includes intake ports 104 for taking external air into thehousing 100 on three outer wall surfaces. These three outer wallsurfaces include an outer wall surface provided with the receiver 80, anouter wall surface provided with the operation panel 85, and an outerwall surface of the lower case 102 facing the upper case 101.

The intake ports 104 are arranged at a position biased on an oppositeside (right direction in FIGS. 11A to 11C) of the receiver 80 and theoperation panel 85 from the longitudinal center portion of the housing100, in the corresponding outer wall surface.

This is because the resistive load 62 is arranged, inside the housing100, at a position biased to the opposite side of the receiver 80 andthe operation panel 85 from the longitudinal center portion of thehousing 100, as shown in FIG. 12 .

In other words, in the second embodiment, the resistive load 62 insidethe housing 100 is surrounded from three directions by the intake ports104 provided on the aforementioned three outer wall surfaces of thehousing 100. As a result, external air taken inside the housing 100 fromthe intake ports 104 by the rotation of the fan motor 92 directly blowsto the resistive load 62.

As shown in FIG. 11E, the side wall on one end side in the longitudinaldirection (one end side in the right direction in FIGS. 11A to 11C)provided with the intake ports 104 in the housing 100 includes exhaustports 105 for discharging air inside the housing 100 to outside. The fanmotor 92 is arranged inside the housing 100 between the resistive load62 and the exhaust ports 105.

External air sucked from the intake ports 104 by the rotation of the fanmotor 92 cools the resistive load 62 inside the housing 100, passes thefan motor 92, and is then discharged from the exhaust ports 105.

Therefore, the housing 100 can inhibit high-temperature air derivingfrom heat generation of the resistive load 62 from staying in thehousing 100, and can efficiently dissipate the resistive load 62.

In the housing 100, since the intake ports 104 are provided on theaforementioned three outer wall surfaces, it is inhibited that all ofthe intake ports 104 are closed when the interlocking adapter 50 isattached to the electric apparatus such as the dust collector 20.Therefore, according to the second embodiment, it is possible to securea path for taking external air into the housing 100, and cool theresistive load 62.

In the housing 100, the side wall including the exhaust ports 105 isprovided with an insertion hole 107 shown in FIG. 12 for inserting thepower cord 53. A protective member 106 for protecting and fixing thepower cord 53 is fitted in the insertion hole 107.

The power cord 53 is drawn from the insertion hole 107 of the housing100 in a state fixed to the housing 100 by the protective member 106.Such an arrangement of the power cord 53 can inhibit an object existingnear the exhaust port 105 from closing the exhaust port 105.

In other words, when an object is at a position facing the exhaust port105, the object abuts on the power cord 53 before closing the exhaustport 105. As a result, it is possible to inhibit the exhaust port 105from being closed by the object.

According to the second embodiment, it is possible to secure the exhaustports 105, and exhaust paths of air inside the housing 100, and inhibitcooling effect of the resistive load 62 from being impaired.

As shown in FIG. 12 , inside the housing 100, the circuit board 71,separate from the resistive load 62, is housed. Various electroniccomponents such as the controller 70 are mounted on the circuit board71. Therefore, inside the housing 100, the resistive load 62 is coupledto the circuit board 71 via a lead wire 120 shown in a dotted line inFIG. 12 .

When the lead wire 120 is in contact with the resistive load 62, coatingof the lead wire 120 may deteriorate due to heat of the resistive load62. When the coating of the lead wire 120 deteriorates, the current pathof the load current may contact surrounding conductors and theinterlocking adapter 50 may fail.

In the second embodiment, as shown in FIG. 13 , the resistive load 62 isprovided with a resistor 62A. The resistive load 62 is further providedwith a heat sink 62B for heat dissipation. In the resistive load 62 assuch, when the coating of the lead wire 120 deteriorates due to heat ofthe resistive load 62, the current path of the load current may contactthe heat sink 62B, and leads to failure of the interlocking adapter 50.

In order to avoid such failures, inner walls of the lower case 102 andthe upper case 101 facing each other are provided with a rib 121 and arib 122, respectively. These ribs 121, 122 inhibit or restrain the leadwire 120 arranged between the circuit board 71 and the resistive load 62from coming into contact with the resistive load 62.

The ribs 121, 122, if formed of a single plate, can reliably inhibit orrestrain the lead wire 120 from coming into contact with the resistiveload 62. However, in this case, a flow path of the air around theresistive load 62 is interrupted, and the cooling effect can beimpaired. Therefore, each of the ribs 121, 122 of the second embodimentis cut out in part and separated into two or more portions. With suchribs 121, 122, air can flow around the resistive load 62, and theresistive load 62 can be cooled.

As shown in FIGS. 11D, 12 and 13 , a hook 112 is provided on the sidewall of the housing 100 on the opposite side of the side wall providedwith the exhaust ports 105. The hook 112 is formed into an L-shape. Thehook 112 is fixed to the aforementioned side wall via the screw 110. Thescrew 110 is configured such that the user grips the head of the screw110 and rotates the screw 110.

The hook 112 of the second embodiment includes an L-shaped plate. Afirst portion of this plate includes an insertion hole 112A forinserting the screw 110. A second portion of the plate faces the bottomof the housing 100. The insertion hole 112A may be a long hole. When theinsertion hole 112A is a long hole, the first portion can be slid so asto bring the second portion into contact with the housing 100 orseparate the second portion from the housing 100 in a state in which thefirst portion is fixed to the side wall of the housing 100 via the screw110.

The hook 112 configured as such can be fixed along the outer wall of thehousing 100, as shown in 14A, or can be fixed in a state pulled out fromthe housing 100, as shown in FIG. 14B.

In the state in which the hook 112 is pulled out from the housing 100,the adapter main body 54 may be fixed to a desired position by hookingthe hook 112 on the hole or a protrusion. For example, as shown in FIG.15 , in case that a hole 36 is provided by which the hook 112 can behooked on the dust collector 20, the adapter main body 54 can beattached to the dust collector 20 by hooking the hook 112 pulled outfrom the housing 100 on the hole 36.

As shown in FIG. 13 , the screw 110 is screwed into a nut 114 providedin the housing 100 and fastened, so that the hook 112 can be fixed tothe housing 100.

Assuming that the nut 114 is provided inside the housing 100, there is apossibility that the nut 114 may fall out inside the housing 100 whenthe screw 110 is detached from the nut 114. When the fallen nut 114moves in the housing 110, the aforementioned circuit inside the housing100 can be short-circuited. Therefore, it may become necessary todisassemble the housing 100 and perform repair work.

Thus, in the second embodiment, as shown in FIG. 13 , the housing 100 isprovided with a gap 109 through which the nut 114 can be inserted fromoutside the housing 100. The nut 114 can be inserted into the gap 109and fixed to the housing 100.

As a result, when the screw 110 is detached from the nut 114, necessityof performing troublesome repair work such as disassembling the housing100 can be eliminated or reduced.

The gap 109 is covered with the hook 112 assembled to the housing 100 bythe screw 110. Such an arrangement of the gap 109 can inhibit the nut114 from falling out from the gap 109 when the screw 110 is detachedfrom the nut 114.

A rod-like coupling portion 108 for inserting the screw coupling theupper case 101 and the lower case 102 is provided on each side of thehousing 100 interposing the screw 110 and the hook 112 therebetween. Asshown in FIG. 16 , a gap through which a fixing band 130 can be insertedis formed between the housing 100 and each coupling portion 108.

Therefore, it is possible to pass the band 130 having a desired lengththrough each gap between the respective coupling portions 108 and thehousing 100. Further, it is possible to attach the adapter main body 54to the electric apparatus such as the dust collector 20 via the band130. Moreover, since the user can use the band 130 to carry theinterlocking adapter 50 to a desired place, usability of theinterlocking adapter 50 can be improved.

As mentioned above, since the operation panel 85 including the LEDs ofthe mode indicator 84A and the error indicator 84B and the switch of theoperating device 82 is arranged on one end side in the longitudinaldirection of the housing 100, the user can operate the operating device82 while gripping the adapter main body 54.

Operation of the operating device 82 by the user switches the modesetting of the interlocking adapter 50, changes the lighting state ofthe LEDs of the mode indicator 84A, and displays the switched modesetting.

Therefore, it may be desirable for the user to grip the adapter mainbody 54 so as not to hide the LEDs of the mode indicator 84A with thehand of the user when operating the operating device 82. Further, it maybe desirable for the user to grip the adapter main body 54 so as not tohide the LED of the error indicator 84B with the hand of the user.

In consideration of the above, in the operation panel 85 of the secondembodiment, as shown in FIG. 11B, the switch of the operating device 82is arranged at a position close to the center in the longitudinaldirection of the housing 100. The LEDs of the mode indicator 84A and theLED of the error indicator 84B are arranged at end sides in thelongitudinal direction of the housing 100.

Therefore, the user can easily confirm the lighting state of the LEDs ofthe mode indicator 84A and the LED of the error indicator 84B whilegripping the adapter main body 54. As a result, usability of theinterlocking adapter 50 can be improved.

The embodiments and the variations of the present disclosure have beendescribed in the above. The present disclosure is not limited to theaforementioned embodiments or variations, and can be practiced invarious modifications.

For example, in the aforementioned embodiments, one example of theelectric apparatus which implements interlocking operation using theinterlocking adapter 50 is the dust collector 20, and one example of theworking machine that operates in an interlocking manner with the dustcollector 20 is the circular saw 10.

However, the interlocking adapter 50 of the present disclosure can beutilized in the same manner as in the aforementioned embodiments in anyelectric apparatuses configured to detect the load current flowingthrough the electric outlet 32 and start their operations, and can causethese electric apparatuses operate in an interlocking manner with aworking machine.

The working machine that operates in an interlocking manner with theelectric apparatus may be an electric working machine other than thecircular saw 10, for example, may be a working machine driven by anengine or air motor, such as an engine cutter, and an air grinder. Ineither case, the working machine may be provided with a device foroutputting the interlocking command signal at the time of operation.

The device for outputting the interlocking command signal may be thetransmitter 42 for wireless signal transmission as in the aforementionedembodiments, or a device that outputs the interlocking command signalvia a signal line (or wire).

Also, in the aforementioned embodiments, the mode setting is set via theoperating device 82 operated by the user. The mode setting may be setusing a mobile terminal, etc. of the user.

Reference Example

In the aforementioned embodiments and the variations, the load currentis supplied to the resistive load 62, and the electric apparatus isoperated in an interlocking manner with the working machine. However, asshown in FIG. 17 or 18 , the electric load to which the load current issupplied may include a capacitive load 58 including a capacitor.

More specifically, the interlocking adapter 50 may be provided with thecapacitive load 58 in an input path of the AC voltage from the AC plug52, and configured to supply an AC current to the capacitive load 58 inresponse to the switching part 64 turned on.

In the interlocking adapter 50 configured as such, since the AC current(reactive current) having a phase advanced by 90° with respect to the ACvoltage flows through the capacitive load 58, loss in the electricapparatus can be reduced. Therefore, occurrence of problems such as heatgeneration deriving from the load current can be inhibited, andeventually the interlocking adapter 50 can be downsized.

In the interlocking adapter 50 shown in FIG. 17 , the switching part 64is provided at the output stage of the full-wave rectifier 60. Theinterlocking command signal from the receiver 80 is received by thereception input device 86 including the light receiving device.

When the light receiving device of the reception input device 86 becomesthe on-state at the time of receiving the interlocking command signal, aDC voltage supplied from the control power supply 74 is applied to abias circuit 202 coupled to the gate of the switching part 64 so as toturn on the switching part 64, and the load current is supplied to thecapacitive load 58.

The bias circuit 202 may be provided with a voltage dividing circuitformed with a resistor R1 and a resistor R2. The control power supply 74may be provided with a Zener diode ZD. The control power supply 74 mayfurther include a resistor R0 through which a breakdown current flows tothe Zener diode ZD by applying a reverse bias voltage from the diode 72to the Zener diode ZD. The control power supply 74 may further include acapacitor C0 that stabilizes a power supply voltage generated by thebreakdown current flowing through the Zener diode ZD.

Utilizing the capacitive load such as a capacitor as the electric load,the configuration of the interlocking adapter 50 can be extremelysimplified.

The interlocking adapter 50 shown in FIG. 18 is provided with anoscillator 204, and a resistor R2 that converts a light receivingcurrent flowing through the light receiving device of the receptioninput device 86 into a voltage, in addition to the configuration of theinterlocking adapter 50 shown in FIG. 17 .

According to the interlocking adapter 50 configured as such, setting anoscillation frequency of the oscillator 204 to a frequency higher thanthe frequency of the AC voltage can turn on and off the switching part64 twice or more at each cycle of the AC voltage at an output from theoscillator 204.

Therefore, it is possible to shorten the supply period of the loadcurrent via the capacitance load 58 and supply the load current withlower loss.

A plurality of functions of one component in the aforementionedembodiments or variations may be achieved by a plurality of components,and a single function of one component may be achieved by a plurality ofcomponents. Also, a plurality of functions of a plurality of componentsmay be achieved by one component, and a single function achieved by aplurality of components may be achieved by one component. Further, someof the configuration of the aforementioned embodiments may be omitted.At least part of the configuration of any of the aforementionedembodiments may be added to or replaced with the configuration of theother of the embodiments. Any aspects included in the technical ideaspecified from language as set forth in the appended claims areembodiments of the present disclosure.

What is claimed is:
 1. An interlocking adapter comprising: a plug configured to be plugged into an electric outlet in an electric apparatus; a first input path and a second input path configured to receive an alternating-current voltage from the plug; a capacitive load on the first input path; a full-wave rectifier including a first alternating-current input, a second alternating-current input, a first direct-current output, and a second direct-current output, the first alternating-current input being coupled to the first input path through the capacitive load, the second alternating-current input being coupled to the second input path, and the full-wave rectifier being configured (i) to rectify a full wave of the alternating-current voltage received via the first alternating-current input and the second alternating-current input and (ii) to thereby generate a rectified voltage between the first direct-current output and the second direct-current output; a switch electrically coupled to the first direct-current output and to the second direct-current output, the switch being configured to be switched between an on-state and an off-state, the switch in the on-state being configured to complete a current flow path between the first direct-current output and the second direct-current output through the switch, and the switch in the off-state being configured to interrupt the current flow path; and a reception input circuit configured to receive an interlocking command signal via a receiver, the interlocking command signal being wirelessly transmitted from a working machine, the receiver being configured (i) to wirelessly receive the interlocking command signal and (ii) to convert the interlocking command signal received, into light, the reception input circuit including a light receiving device configured (i) to be applied with a direct-current voltage and (ii) to receive the light to thereby turn on, and the reception input circuit being configured to turn on the switch in response to the light receiving device turning on or having turned on.
 2. The interlocking adapter according to claim 1, further comprising: a driving voltage generation circuit configured to generate a driving voltage to turn on the switch, wherein the reception input circuit is coupled to the switch via the driving voltage generation circuit.
 3. The interlocking adapter according to claim 2, wherein the driving voltage generation circuit includes a voltage dividing circuit.
 4. The interlocking adapter according to claim 1, wherein the first direct-current output is configured to output a rectified positive voltage, further comprising: a control power supply coupled to the first direct-current output, the control power supply being configured to generate a constant direct-current voltage to turn on the switch based on the rectified positive voltage.
 5. The interlocking adapter according to claim 4, wherein the control power supply includes a capacitor and a Zener diode coupled in parallel with one another.
 6. The interlocking adapter according to claim 4, further comprising a diode having an anode and a cathode, the anode being coupled to the first direct-current output, and the cathode being coupled to the control power supply.
 7. The interlocking adapter according to claim 1, further comprising a surge absorber coupled between the first input path and the second input path.
 8. The interlocking adapter according to claim 7, wherein the surge absorber includes a varistor.
 9. The interlocking adapter according to claim 1, wherein the electric apparatus includes a dust collector.
 10. The interlocking adapter according to claim 1, wherein the light receiving device is a unidirectional switch.
 11. The interlocking adapter according to claim 10, wherein the light receiving device is a phototransistor.
 12. The interlocking adapter according to claim 1, wherein the first direct-current output is configured to output a rectified positive voltage, further comprising: a control power supply coupled to the first direct-current output, the control power supply being configured to generate, based on the rectified positive voltage, the direct-current voltage to be applied to the light receiving device.
 13. An interlocking adapter comprising: a plug configured to be plugged into an electric outlet in an electric apparatus; a first input path and a second input path configured to receive an alternating-current voltage from the plug; a capacitive load on the first input path; a full-wave rectifier including a first alternating-current input, a second alternating-current input, a first direct-current output, and a second direct-current output, the first alternating-current input being coupled to the first input path through the capacitive load, the second alternating-current input being coupled to the second input path, and the full-wave rectifier being configured (i) to rectify a full wave of the alternating-current voltage received via the first alternating-current input and the second alternating-current input and (ii) to thereby generate a rectified voltage between the first direct-current output and the second direct-current output; a switch electrically coupled to the first direct-current output and to the second direct-current output, the switch being configured to be switched between an on-state and an off-state, the switch in the on-state being configured to complete a current flow path between the first direct-current output and the second direct-current output through the switch, and the switch in the off-state being configured to interrupt the current flow path; and a reception input circuit configured to receive an interlocking command signal transmitted from a working machine, the reception input circuit being configured to turn on the switch in response to the reception input circuit receiving the interlocking command signal; and an oscillator having an oscillation frequency, the oscillator being coupled to the reception input circuit, and the oscillator being configured to turn on the switch based on the oscillation frequency.
 14. The interlocking adapter according to claim 13, wherein the oscillation frequency is higher than a frequency of the alternating-current voltage.
 15. The interlocking adapter according to claim 13, further comprising: a driving voltage generation circuit configured to generate a driving voltage to turn on the switch, wherein the oscillator is coupled to the switch via the driving voltage generation circuit.
 16. The interlocking adapter according to claim 15, wherein the driving voltage generation circuit includes a voltage dividing circuit. 